In a large bowl, whisk together the condensed milk and water until combined. Sprinkle in the instant banana pudding mix and whisk until blended. Refrigerate this mixture for at LEAST four (4) hours.

Once mixture has thickened and chilled, prepare your whipped cream. Whip the heavy cream with the whisk attachment in your stand mixer until stiff peaks form. Fold in one third of the whipped cream into the pudding mixture until combined. Then, fold in the rest of the whipped cream, careful not to deflate the airiness of the whipped cream. Gentle folds is the secret.

In Mason Jars, or in a large trifle, put in a handful of Nilla Wafers; top with sliced bananas. Pipe or spoon the banana pudding into the jars about halfway. Repeat layers of Nilla Wafers and bananas, then add more pudding on top. Repeat with remaining jars or finish up the trifle. Store leftovers in the fridge, covered, up to 2 days.